An electronic alarm clock is an important apparatus for alert in our daily life and work, and that embedded in a mobile phone for achieving an indispensable function of the mobile phone has increasingly been widely accepted by users as an alert apparatus for alert, memo and the like. With the utilization of electronic alarm clocks and popularization of electronic alarm clocks in mobile phones, some problems emerge in their use.
When a customized time of an electronic alarm clock is up, the clock will enter an alert mode (including shake and ring), in which if the shake is weak or the ringing tone volume is small, a user often cannot be aware of it, thus failing to achieve the alert purpose; and if the shake is too strong or the ringing tone volume is large, the user may be frightened by abrupt shaking and/or ringing, especially when the user is in sleep and then suddenly waken up, sudden acceleration of heart beat could be aroused, thereby causing serious cardiovascular injury to human body.
In view of the foregoing problems, there is a need of an electronic alarm clock with a more humanized alert function. Thus an electronic alarm clock with an optical detection function comes out as required, the working principle of which is to set the ringing tone volume in a ringing alert mode according to the light intensity of the place where the electronic alarm clock is located. However, the optical detection function can be affected by many factors including weather, season, the location of the electronic alarm clock, etc., and therefore the foregoing problems can not be properly solved by means of setting the ringing tone volume in such a way, and the purpose of alerting within the shortest time on the premise of giving the user good experience can not be achieved.